Air-compressing system.



10.869,799. 1 PATENTED 0972.291907.

AIR COMPRESSING SYSTEM.

APPLIOATION FILED rms. 1a, 1907.

' 4 SHEETS-SHEET 1.

NVENTO? DELEEHT BAUER Ano/#Nays PATENTED '"ocT. 29

AA. SABER. AIR GOMPRESSING SYSTEM.

APPLICATION FILED FEB. 18,1907.

4 SHEETS-SHEET z.

Y /NVENTOH ADELBER'I BAUER.

W/TNESSES AT TOHNEYS A No. 969,739. f PATENTED 00T. 29. 1907.

A. SAUER. AIR GOMPRESSING SYSTEM.

APPLICATION FILED IFBB. 18,1907.

4 SHEETS-SHEET 3.

/NVENTOH ADELBERT EAUER 'Anm/VHS PATENTED 00T. 29| 1907.

A. SABER. AIR GOMPRESSING SYSTEM. APPLICATION FILED I'EB.18. 1907.

4 SHEETS-SHEET 4.

/vl/ENTOH ADELBEBT BAUER W/TNESSES ATTUHNEYS UNITED y sTATiEs PATENT osiuon.

ADELBERT SAUER, OF PITTSBURG, PENNSYLVANIA.

AIR-COMPRESSING SYSTEM.

Specification of Letters Patent.

Patented Oct. 29, 1907.

Applimionmed reti-nary 1s, 1907. serai No. 358.010.

dwellings and for the production of gas for illuminating purposes.

In my system the pressure of a motive fluid is utilized to create a suction for the generation of anfinllowing current of/atmospheric air which is combined lor mixed intimately with the motive fluid and is stored in a reservoir chamber until such fluid obtains a pressure suflicient to overcome the rmt/ance of a regulating vent valve; and such inflowing current4 drawn into the apparatus by suction created by injector devices operated under the high pressure of -the motive fluid sets in motion a current fan that acts on thecor'nmingled motivefluid and air current so that the pressure'of the motive fluid isaugmentedduring the passage of said motive fluid from the combining chamber to 'the reservoir,

chamber.

My invention also contemplates the provision, of heating appliances situated in the reservoir chamber for the motive fluid for the purpose o expanding the latter and increasing the pressure thereof, such heating appliances being adapted for the consumption of carbonaceous fuel and for the gaseous products resu1ting4fromholder for the purpose of washing and storing the illuminating gas previous to drawing off the same for consumption at illuminating burners. l

The motive fluid in my system may extend its energy iu the performance of'useful work to drive motors and other machinery and in this adaptation 'of the invention the motor has 'its exhaust connected with a member of the circulating system for .the return oithe partially spent or exhausted motive fluid to such circulatory sys; tem to be regenerated by passage through the primary generator and bypintermingling with the high pressure motive fluid thereof, thus utilizing the exhaust however its pressure may be reduced in the system.

Toenable others to understand the invention I have villustrated the same and different adaptations thereof in the accompanying drawings forming a. part of this specication, and in which Figure 1 is a vertical sectional elevation ofthe comprssor generatorivith the several elem'ents'which are combined -with the same. Fig. 2- is a transverse horizontal sectional view on'tlie plane indicated by the dotted line 2-2 of Fig.A 1. Fig. 3 is a similar view on the plane indicated bythe dotted line 3-3. in Figi 1. Fig. 4 is a vertical sectional elevation of another embodiment of the invention in which a heater is utilized as the medium for expanding the initial pressure. of ythe motive uid and illustrating the generator actively com' bined with a motor. Fig. 5 isa vertical sectional ele` vation at right angles to Fig. 4 and on the plane indicated by the dotted line 5-5 of said Fig. 4f. Figs. 6 and 7 are transverse horizontal sectional views on the planes indicated by dotted lines 6 6, 7 7, respectively of Fig. 5. Fig. 8' is a vertical sectional elevation showing one adaptationof the generator for the purpose of ventilating the building and of driving motors therein; Fig. 9 is another vertical sectional elevation illustrating an adaptation of the primary generator and the heating furnace for the productionl of an illuminating .gas for lighting the building. Fig. 10 is a diagrammatic View of the/system in which the energy ofthe motive fluid from a number of the compressors or generators may be transmitted lfrom a central station to a number of buildings or dwellingsY to be converted or translated into mechanical energy by motors therein. Figs. 11 and 12 arevertical cross-sectional elevations of the central station ap .paratus on the planes indicated by the dotted lines 117-11, 12-12, respectively of Fig. 10.

Like numerals of reference denote like and corre sponding parts in each of the several figures of the drawings.

The' compressor o"r generator is designated in its entirety by the numeral 1 for'the purpose of conveniently referring thereto in the subsequent description of the circulatory system which may include one oraI series of generators. This generator has a shell` 2 preferably cylindrical in form and closedat its'bottom so as to form therein a reservoir chamber 3 designed to combine the high pressure motive fluid. The upper end of the shell 2 is closed substantially by an air inlet shell 4 which is bolted or otherwise united rigidly to the top or open upper end of the generator shell 2. This air inlet shell 4 is provided with a central annular valve seat 5 pierced at intervals by a plurality of radial inlet ports 6 and in this valve seat is slidably fitted a gravity valve 7 which is adapted to fit snugly to the seat and has its stem fitted slidably and loosely in a fixed guide bridge 7'. An injector cone 8 is `flanged and united rigidly to the air inlet shell 4 so as to have its axis in alinement with the longitudinal axis of the generator shell 2 and air inlet shell'4 and within the injector cone is arranged the air inlet cone 9 which may form a part of the chambered Vair inlet shell 4. The cone 9 communicates with the annular chamber formed thereof; and this arrangement of the two cones pro' duces a narrow slit or orifice A11 atthe apex of the in# ternal cone 9. The external injector cone 8 is extended or prolonged beyond the open upper end ofthe internal v air inlet cone 9 thereby forming a combining chamber 12 within the injector cone and beyond the discharge end of the air inlet cone and into this .combining cham;

ber is delivered thel high pressure4 motive fluid which passes through the tapering annular passage 10 and the -air current under ordinary atmospheric pressure which is delivered byithe chambered inlet shell 4 and the internal cone'9, the current of high pressure motive fluid and the current of atmospheric air under normal atmospheric pressure being intimately combined orintermingled in the chamber 12. The high pressure motive liuid'from the reservoir chamber 3 of the generator is conveyed or conducted through the chambered air shell 4 without communicating with the latter by means' of the high pressure tubes 0r pipes 13 which communicate with the reservoir chamber 3 and'extend through the chamber of the air inlet shell 4 so as to discharge intov the annulartapered passage 10 between the cones 8, 9, and the movement of this current of high pressure fluid through the annular passage between the cones and -through the narrow slit or orifice 11 creates a strong suction through the air inlet shell 4, the current of atmospheric air flowing lthrough which lshell is of sufiicient strength to raise'the gravity. valve 7 and thus 'insure the passage of the air current into the injector devices of the generator.

In the annular tapered passages 10 between the injector cones 8, 9 is provided a series of spiral ribs or fins 14 which serve to properly space the inner cone 9 with relation to the outer cone 8 and these spiral ribs are tapered longitudinally from their lower ends to their upper ends, the upper ends of saidribs being reduced to a thin edge and terminating in the horizon- -tal plane of the open upper end of the inner cone 9.' The spiral depression of the ribs 14 between the tw'o cones gives the current of high pressure motive fluid a spiral or whirling motion as said -currenttraverses the annular tapered chamber 10 and the whirling high pressure motive fluid is thus caused to combine more intimately with the air current than would be the case if high pressure current were injected in a plane parallel to the path of air current.

15 denotes a pressure inlet substantially at rightangles to the vertical axis of the generator shell and its cones, This'pressure inlet is tapered or conical and it is united to or made integral with the cone 8. In the chamber of the pressure shell is situated a propeller which is driven by an exterior current fan presently described so that the propelling wheel will act upon the current of high pressure motive fluid and air which is delivered teY the shell 15 from the generator.

In the embodiment of the invention represented by'Fig. 1 the initial supply ofthe high pressure motive fluid is obtained from a high pressure charging tank 16 which is located exterior to the generator shell 2 This charging tank 16 has an inner pipe connecting it with the generator shell 2 at a point below the chambered air inlet shell 4 and in this pipe connection is stop cock 18vwhichl may be closed to shut off communication through the high pressure tank to the reservoir chainber of the generator. When the pressure in the reservoir chamber of the generator attains a high limit the connection 17 is closed from the high pressure tank and the generator itself supplies the high pressure fluid to the injector devices thus insuring the lcontinuous operation of the apparatus automatically until the pressure in the generator is reduced substantially. During the maintenance of the high pressure motive fluid in the reservoir chamber of the generator the high pressure tank may be stored or recharged with a portion of Such .high pressure motive fluid from the generator chamber and to this end Iprovide a return pipe connection 19 between the lower. portion of the generator chamber and the high pressure tank such return pipe connection19 having a stop cock'20 which is open -to establish a connection between the generator chamber and the tank. Normally the stop cock 20. is closed so that the` high pressure fluid from the tank 16 may pass through the connection 17 to the generator \chamber b ut in' recharging the high pressure tank the stop cock 18 in the pipe connection 17 should be closed. The air is supplied to the chambered inlet shell 4 by a pipe 21 which has its lower end coupled to said shell 4 and in this pipe 21 is a stop cock 22 which normally remains open but which may be closed to stop the operation of the' apparatus. This air inlet pipe 21 is operatively connected with a casing 23 of a current fan and said casing is provided with alined shaft bearings 24 which accommodate the fan shaft 25. This fan shaft is prolonged or'extended through a shaft bearing 26 and a stuffing box 27 on the enlarged end of the pressure inlet 15 which is adjacent to the fan casing 23 so that one end of the fan inlet 25 extends part way through the pressure inlet 15. Within the fan casing l23 is arranged a current fan 28 having a-series of radial blades 29 secured to a hub which is mounted rigidly on the fanshaft 25 at the place where it passes through rot the fan casing'23 and this current fan is rotated by the impingement of the inflowing air current which is drawn through the fan casing 23 by the suction due to the action of the injector device forming a part of the generator and receiving the high pressure motive fluid from the reservoir chamber 3 of said generator.

The fan casing 23 is provided on opposite sides of thel chamber which receives the current fan 28 with the partitions 30, 31 which are suitably secured in place Within the fan casing parallel to the side walls thereof one of said partitions forming with one u all of the *faul casing an'air inlet chamber 32and the other partition forming with the opposite Wall of the ian casing an exhaust chamber 33. Atmospheric air is supplied to the chamber 32 by inlets 34 in one Wall of the fan casing and the air from the chamber 32 is supplied to the fan chamber by a plurality of ports 35 which are formed in thepartition 30 on one side of the rotary current fan. In the partition 31 on the opposite side of thc current fan are provided a plurality of ports 3G which establish communication between the fan chamber 33 and the exhaust chamber 33 and with this exhaust chamber 33 communicates thc air pipe 2l that conveys the current ecosse vof air from the fan casing to the chamber ofthe air inlet shell 4. i On that portion of the fan shaft 25 which is 'con- .tained within the pressure shell l5 is secured a propeller fan 37 having its blades arranged spirally on the fan shaft 25 and extending in a general longitudinal direction of said shaft and this propeller fan 37 may bel set-to lie in a plane with its longitudinal axis at right angles to the plane of the current fan 28 the blades oi which are radial to the fan shaft, The propeller fan 37 has its spiral blades extending across a port between the combining chamber 12 and the lpressure shell 15 and this propeller fan is rotated by the shaft 25 in the chamber of the pressure shell soas to expel the commingled current of motive fluid and air from the generator and in a measure augment the pressure of the motive fluid. f

A pressure pipe 38 extends from the shell 15 to the lower part of the reservoir chamber 3 and this pipe conveys the motive fluid from the generator combining devices to the reservoir chamber or storage in the latter until the pressure of the motive fluid is increased by the combination of the atmospheric air therewith to such an extent as to bring the motive fluid to a point where it may be advantageously employed in the performance of useful work. During the operation ofthe charging ofthe reservoir chamber 3 and of augmenting the pressure of the lmotive fluid to bring the latter 4up to the point where it may be used advantageously the motive fluid is prevented from passing from the generator by an automatic vent valve 39, the shell 40 of which-iscoupled or united 1to the shell 15 at thef-point beyond 'the communication of the pressure pipe 38 with said shell 15. This vent -valve shell has a valve seat 41 upon which the slidable vent valve39 is vnormally pressed by a spring 42, the tension of which may be regulated by a screw 43 and from this ventvalve leads a'circulating pipe 44 which is adapted to'convey the motive vfluid to a distributing or circulating system from which-the motive fluid may be taken to operate suitable translating machines for Ventilating purposes, etc,

`In the operation of the apparatus thus far described the high pressure tank '16 'is stored -with motive fluid under an exceedingly high pressure -romany suitable source of supply and to start the apparatus in action the valve 18 is opened to admit the fluid to the chamber 3 of the generator. This motive fluid rushes through the pipes or tubes 13 and the passage l0 the spiral ribs of which impart a whirling motion to the current of the motive fluid and this motive fluidl escapes from the orifico or slit 11 into the combining chamber 12 withsuicient energy to create a suction through the air inlet cone 9 which it will be recalled has free communica.- tion with the outside atmosphere. an inflowing current of air through the fan casing, the pipe 21 and thedchambered air inlet 4 and the inflowing current of air rotates the current wheel 28 and elevates the valve 7 from its seat thus permitting the air current to pass through the cone 9 and be combined in the chamber l2 with the high pressure motive fluid. This motive fluid traverses the shell 15 and its pas sage through the latter is facilitated by the action of the expelling fun 37 and from the shell the current of motive fluid passes through the pipe 38 back to the This suction creates reservoir Acharmloer 3. This circulation inthe generator is maintained until the motive flu-id is augmented charging tank 16 iand in 'lieu rthereofemploy a heating furnace which serves as a medium `:for expand ng the initial supply of motive fiuid obtained from a .reserve v storage dome ormingoneoftheielements'ofrthe generator. The heating furnace embodies-a closed chamber 45 which is situated -in or centainedxdirectly within fthe lreservoirchamber 3 of thegenerator and this furnaoeis primarily adapted for the Vconsumption of carboneheous fuel such as coal. This furnace chamber Ihas an ordinary grate 46 which-is supplied with air to support com- 'bustion 'from an air -flue 47 suitable doors 475L which may-be closed WhenLthe generator is in service; and with this closed chamber communicates a charging chute' 48 adapted normally to lbeclosed by a door 49 such charging chuteexltendingoutside of the generator shell 2 so as to .provide for the .introduction of =fuol from 'time to time into the-furnace chamber without permitfting they motive fluid to'escape'fromrthe generator. The

furnace v chamber :is .also equipped with an injector burner 50 onetypeof'which consists in theemployment of an internal cone 51 andan outer cone 52 adapted to supply-respectivelythe gaseous'produots'of-combusticn from the -furnacechamber and'the aeriform motive fluid 4from'the reserve dome; circulating pipe 53 'is 'con- 'nectedvtoltheupper end of ithe-closed furnace chamber and extends through y'the shell ofthe generator to the outside thereof and Vfrom this :pipe 531leads a lbranch pipe 54 which is'connected tothezinternal cone 5'1 ofrthe inj ector burnerfor-thepurpose of conveying tothe =lat 'ter the smoke and'l other gaseous products of combustion resulting from the burning'of the carbonaceous fuel-on the-grate in the closed furnace chamber. The aeriform nioti-ve'fluid is conveyeddromthe reserve storage dome 57 tothe outerl cone 52 ofthe injector burner bynieans of a Apipe 58 which is suitably attachedfto the d rum 51 andthe burnencone 52and its connecting -pipe-584 con- -tains a stop cock 59 and a pressure regulator 60, thelat- 'ter being situatedinthepipe 58 adjacentto theinjector burner. The gas Apipe 53 between-the closed furnace chamber and 4the injector burner -isequipped ywith a vent pipe 55 which may'lead outside offthe-building if desired and .infthis vent Apipe is a damper or valve 56 which serves normally topreventzthe escape of the passage of' the products of combustion tothe vent pipe and 'to directthesameinto thebranch Milead-ing-to'the injector burner 50. The reserve storage dome 57 is connected to or mounted uponzthe'pressure shell l5 so asto communicate l,therewith and the :motive fluid 4under high pressure is stored or contained :partially -within this dome thus providing a source of aeriform high pressure motivefluid suflicient to furnish the initial'energy for the operation of the furnace in starting-up the apparatus. The air contained within' the reservoir chamber 3 is expanded by the energy of the furnace situated within said chamberand the motive fluid .passes from current of air to the chambered shell 4, the fan casingl the current ian and the propeller ian, shown by Figs. 4 and 5 are identically the same in construction as in the apparatus represented by Fig. 1 but in said Figs. 4 and 5 I'employ a pressure regulator 63 at one of the air inlets 34 to the air supply chamber oi the ian casing.

The compressor or generator represented by Fig. 4 is operatively connected with'a motor 64 which is supplied with thecompressing motive ii-nid underhigh pressure by providing the supply pipe' 65 which is ati taclied to the reserve storagedrum 57 and connected with the feed inlet 66 oi the motor. The exhaust from the motor is not discharged into the atmosphere but in lieu thereof the exhaust pipe 67 is connected to the suction inlet 34 of the ian casing. I do not deem it neces- -sary to specilically describe the construction oi the motor 64 because the same forms the subject-matter oi a; separate application but attention is at this point called to the fact that the exhaust from the motor is returned to the generator by Way of the cuirent fan so that the motive iiuidnotwithstanding the reduction oi its pres sure may be regenerated by the combustionfwith the high pressure motive fluid in the 'generator due to the action oi the injector devices therein.

In the adaptation of my invention represented by Figf'8 the generatorisshown' as being connected with an out-going or supply main 70 by means of a connecting pipe 7l which is attached to the shell oi the vent valve on the pressure shell 15, and this outgoing main constitutes one pipe of a circulating system that may be installed ina building .or dwelling for the purL pose of Ventilating the latter and to furnish the energy to operate the translating devices or motors. This circulating system is represented by said Fig. 8 as having a series of discharge nozzles 72 adapted to supply the aeriform fluid to the various rooms or compartments within the buildingand from this circulating system leads pipe'connections by which the compressed motive luid may be conveyed to` one or more motors or vother translating devices 73, theexhaust from which is returned to another pipe 'connection of the circulating system.v In lieu of taking the atmospheric air from the room or apartment in which the generator lmay be located I may provide a Yfresh air inlet pipe 74 which extends to the outside 0i the building and is attached to one of the air inlets to the casing oi the current ian.

In Fig. 9 of the drawings I have illustrated another adaptation -of the invention in which a part oi the gaseous products of combustion from the furnace chamber of the apparatus represented by Figs. 4 and 5 may be conveyed to agas storage tank 75 thus adapting the gaseous products of combustion' for the purpose oi illuminating the building. The closed furnace chamber 45 has a gas pipe 76 connected to its upper end and this pipeextends tb the gas tan-k 75. The delivery end of the pipe 76 has a goose-neck bend 77 which terminates in the water bath of the tank 75 so as to discharge the gaseous fluid into the tank andas the'gas scarsa rises through this water bath it is cooled and washed to fit it for service as an illuminating medium. vThe pipe 76 is provided with a cock or valve 78 to cut off communication between the furnace and the gas tank and such ltank has a water inlet pipe 81 and a water overflow pipe 82. The gas for illuminating purposes is conveyed from the storage chamber of the tank 75 by thesupply pipe 79 which is suitably attached to the tank and in this off-bearing'gas pipe is a valve 80 which is controlled automatically as by a spring to keep the gas under pressure within the tank and prevent its pas- `sage to the burner until the pressure attains a limit sufficient to overcome the resistance oliered by the spring. The air necessary to support combustion at the injector burner oi the furnace is supplied by the pipe 83connected to the reserve storage dome and the outer cone of the said burner and said pipe 83. is equipped with a pressure regulator 84 that controls the pressure of the aeriform motive duid which may be admitted to the injector burner. The gaseous iuid supplied to this injector burner is attained by the employmentrof a gas pipe 85 connected to the storage tank 75 and the inner cone of the injector burner and this pipe 85 has a suitable stop cock 86.

In Figs. 10, 11 and 12 of the drawing I have illustrated a circulating system adapted for use in connec` tion with a force motor at a central station and to this force motor is connected a series of devices which form a part of the circulating system and which are supplied with a motive iiuid from a numberoi generators 1 so that the combined energy of the series of cur- -rents from such generators 1 may be exerted upon the central station motor which in turn drives or impels a series of currents into another series of devices which may lead to a number of compartments,in a. dwelling or to a number of buildings. The central station motor 87- is housed or contained within a suitable casing 87 having bearings for a shaft 88 and on the ends of this shaft are propeller wheels 89 which operate in suitable lcompartments oi the shell 872. The mains of the circulating system which lead from a series of generators 1 are connected at 90 and discharge to one of the propeller wheels 89 so as to rotate the forcing motor 87 and these currents under pressure are so delivered to the forcing motor 87 which discharges the motor fluid to the other propeller Wheel 89 and the ofibearing mains 91, said mains 91 leading to a number of buildings so as to supply the high pressure motive fluid thereto and enable said fluid to be utilized in the performance of useful work.

It should be stated that Water is supplied to reservoir chamber 3-see Fig. 4-and may be maintained at the height indicated by transverse dotted line by any suitable provision of supply or inlet pipe, escape steam pipe, and regulating valves; also, suitable fire-brick, or other lining is provided in practice for the furnace or combustion chamber.

Having thus described my invention what I claim 1. In an air compressing apparatus a. generator having a reservoir chamber' and an injector member which has free communication with said chamber', an air chamber having a cone situated within the rst named injector member and arranged to direct a current of atmospheric air tothe currentof high pressure motive fluid supplied to said injector member, and a propeller in the chamber forming a reservoir chamber, a chambered'air shell having a check'valve, an injector having 'its members communicatingrespectively with the' chambers of the generator and air shell, a supply pipe to the air shell, a fan casing to' which the supply pipe is coupled, and a shaft carrying the cnrrent-andpropeller wheels, substantially as de- 3. In an air compressing apparatus, the combinationof a generator shell having a reservoir chamber and a vaived air chamber, a combining injector device having its members connected respectively Ato said reservoir and air ycha'mbers, 'a current-'fan in the conduit leading through the air chamber and adapted to be rotated by the air current turned by the suction created through the air chamber by the injector device, and a propeller fansituated in the chamber receiving the motive uid from -the injector devices and actuated by the current fan,` substantially .as described.

4. In an air compressing apparatus-a generator having a reservoir chamber andan air chamber and a combining injector device having its members communicating with said chambers combined with a shell which lreceives the motive iiuid from the injector device and a propeller wheel arranged in said shell for the purpose described, substan tiaily as set-forth 5. In an air compressing apparatus the combina-tion 'with the generator having a reservoir chamber for a motive iiuid and-an injector device, of an air fan casing' Lprovided with an airI discharge member ofsaid injector device and provided with perforated partitions forming a series of 4chambers within said fan casing, a shell receiving the motive iiuid from the combining injector device of the generator, and a' single fan shaftcarrying a` current fan4 and a propeller fanA which are located, respectivelyv in:

' the casing and the shell, substantially as described.

6.In an air compressing apparatus the combination of a generator having a reservoir chamber and a combining thegenerator and having aainjector burner, areserve storage dome receiving the motive uid from the generator and equipped with apipe connection to' the injector burner of theffurna'ce, and means for supplying gaseous fuel to said injector burner, substantially as described. 8. In an air compressing apparatus the combination of a generator having a reservoir chamber and a combining injector, a reserve storage dome communicating with such generator, a furnace within the reservoir chamber of the generator, an injector bui-ner discharging to said furnace, a `return,pipe 'connection coupled to the furnace, and 4to one member of the injector burner to convey the gaseous products of combustion fr om said furnace to said 'burner and a pipe connection: from the reserve storage dome to theother member ofthe injector burner,substantially as described.. s 9. In an airy compressing apparatus the combination of agenerator having a combining. injector and a reserve storage dome, a fau casing communicating'with one member of the injector, a motor having its 'exhaustl discharging to a port'of the fan casing anda supply pipe connection between' the reserve storagedom and the inlet port of the motor, substantially as described. 10. The combination with the generator, ha/ving a combining` injector of a' current fan-driven by the suction through the injector to create, an iniiow'ing current of air thereto and a propeller driven by the current fan and' operating in the chamber which receives the motive fluid from the injector, substantially as described.

-11. The combination, with a generator, of a combining injector adapted 'to create a suction current of atmospheric air to be supplied to a member ofsaid injector, and

a rotary motor supplied with motive fluid from the generator and having its exhaust connected to the, suction "device of ,the combining injector, substmtiauy as de scribed.

DEL-BERT SAUEB.

Witnesses: y

JOHN McDoNALo, AusrxN -W.` Pacs. 

